1. Field of the Invention
The present invention relates to a vehicle lamp and more particularly to a vehicle lamp that has a shade which covers a light source for preventing the generation of dazzling light rays.
2. Prior Art
It is well known that a vehicle lamp includes an element that is called a shade. The shade covers at least the front end portion of a light source so as to prevent light rays emitted from the light source from becoming dazzling light rays which is generally called a "glare light".
In the above vehicle lamp, however, heat generated by the light source is likely to accumulate within the shade without escaping, which increases the temperature of the area around the light source.
When the temperature of the area around the light source increases, various problems occur. For example, exfoliation of the plating applied to the shade occurs, thus darkening the shade, and the life of the light source is shortened. The heat accumulated inside the shade is also likely to damage a leg portion of the shade which supports the shade to a reflector or a lamp body. So as to avoid this, the leg portion may be provided on the side surface of the shade; however, with this structure, the light rays emitted from the light source and laterally directed will be blocked by the leg portion, resulting in that the quantity of light becomes insufficient.
If the shade is designed so as to cover only the front portion of the light source in order to avoid the heat generated by the light source from accumulating in the shade, the light rays emitted in the lateral and downward directions are reflected by the side surface and lower surface of the reflector, respectively. If this occurs, a pedestrian may be dazzled by the glare of the light laterally emitted from the lamp of the approaching vehicle. The driver of a vehicle may also be dazzled by the glare of the light emitted upward from the lamp of the approaching vehicle if the approaching vehicle has the shade described above. In case of driving in the rain, such a dazzling light may result in optical film phenomenon in the front of the vehicle.